It looks like it’s not supported by Batocera. At least when I look at the Wiki it only talks about Bluetooth pairing or standard USB controllers being supported.
https://wiki.batocera.org/kit_to_get_a_batocera
I have a MayFlash GC USB adapter I can try out to see if it works, but I doubt it because it needs a special driver hack to work on PC properly, so the same driver hack would need to be implemented in Batocera.